1. Field of the Invention
The present invention generally relates to a refrigerant recycling system and, more particularly, to a refrigerant recycling system used for recovery and recharging of a refrigerant of an already existing refrigeration cycle unit such as an air conditioner.
2. Description of the Related Art
Conventionally, when an air conditioner (refrigeration cycle unit) is to be repaired, installed, or relocated, the refrigerant in the refrigeration cycle circuit is discharged (discarded) first, required repair, installation, or relocation is performed, and thereafter a rated amount of a refrigerant is independently recharged in the refrigeration cycle circuit from a refrigerant supply/discharge port. When the capacity of the air conditioner is lowered due to natural refrigerant leakage, the refrigerant loss amount is not clear. Therefore, the refrigerant in the refrigeration cycle circuit is discharged to the air in a similar manner, and a rated amount of a refrigerant is recharged in the refrigeration cycle circuit from the refrigerant supply/discharge port.
In such an existing refrigeration cycle unit, fluorocarbons, the use of which is regulated currently, are widely used as the refrigerant. However, it is pointed out that, since fluorocarbons have a very high chemical stability, when they are discharged in the air, they reach the stratosphere to destroy the ozone layer. For this reason, fluorocarbons are believed to be a factor that causes the increase in ultraviolet rays radiated from the universe onto the earth and the greenhouse effect in which the earth surface temperature is increased.
Even if the other refrigerants, such as R-22 etc., which are had small of ozone destroying coefficients, are used, it is a waste of resources if they are directly discharged in the air, and is thus not preferable.
Hence, a development of a refrigerant recycling system, which enables a required work for a refrigeration cycle unit such as repair and relocation without discharging a refrigerant, such as fluorocarbon or its substitute, in the air, is urgently sought for in various fields.
In development of such a refrigerant recycling system, the following points must be considered:
(a) the refrigerant should not be damaged during recovery;
(b) the refrigerant recovery/recharge amount can be measured easily and correctly;
(c) the processing time is short; and
(d) a lubricant in the compressor of the refrigeration cycle circuit should not be recovered together with the refrigerant.